A display device with a display panel is used to present computational outputs. Generally, a display device is an independent unit separated from a computer. A display device is electrically coupled to a computer to receive video signals from the computer and present images. As a display device and a computer are both independent devices, they should occupy considerable space. For example, a PC (Personal Computer) usually has to connect with at least one external display device to present the computational results or the stored information. Now, the traditional CRT (Cathode Ray Tube) display device is usually replaced by an FPD (Flat Panel Display) device having a much smaller volume, such as LCD (Liquid Crystal Display). However, the placement of an FPD device still troubles users. For example, when the space is limited, an FPD device will crowd out other accessory devices, such as a keyboard or a mouse. With the development of digital products, computers are widely used in home multimedia systems to function as a signal source for a large-size display device. When a video or pictures are playing, a user cannot view process-control information or browse webpages unless he interrupts video playing, which will interfere with the other audience. Refer to Taiwan patents No. 558027 and No. 200742958, wherein a display device is integrated with a computer. The abovementioned prior arts indeed reduce the space occupied by a computer and a display device. However, the irregular protrudent surfaces thereof impair the collocation of the computer and other A/V devices, such as an audio amplifier, or even harm aesthetics of the entire appearance.